This invention relates to heating matter and is particularly, but not exclusively, applicable to methods of heating matter using apparatus as disclosed in Specification EP-B-68853 and copending British Specifications Nos. 2202618A, 2203670A, 2205049A and 2211597A, and in which matter is moved in a band continuously along an annular path in an annular zone by directing fluid flow into the zone over the annular extent thereof with both circumferential and vertical flow components. It will be understood that by utilising heated fluid for the fluid flow over at least a portion of the annular extent of the zone, there will be a heat transfer between the heated fluid and matter as the heated fluid passes through the band thereby heating the matter.
A gaseous mixture which is reactable to produce heat may be used to provide a heated fluid flow, for example the gaseous mixture may be a combustible gaseous mixture, typically comprising an air-gaseous fuel mixture.
However it will be understood that, for the above process of producing a heated fluid flow to be efficient in a method of heating matter as described above wherein the heated fluid flow passes through a band of the matter which is moving continuously along an annular path in an annular zone, the reaction which produces the heated fluid flow should occur in the zone and must be rapid to ensure that the reaction is substantially completed within the extent of the band, which for example is typically 50 mm deep.